Immunohematopoietic modulation by oral ß-1,3-glucan in mice infected with Listeria monocytogenes.

In this study we demonstrated that the oral administration of ß-1,3-glucan (Imunoglucan®) protects mice from a lethal dose of Listeria monocytogenes (LM) when administered prophylactically for 10 days at the doses of 150 and 300 mg/kg, with survival rates up to 40%. These doses also prevented the myelosuppression and the splenomegaly caused by a sublethal infection with LM, due to increased numbers of granulocyte-macrophage progenitors (CFU-GM) in the bone marrow. Investigation of the production of colony-stimulating factors revealed an increased colony-stimulating activity (CSA) in the serum of infected mice pre-treated with Imunoglucan®. The treatment also restored the reduced ability of stromal cells to display myeloid progenitors in long-term bone marrow cultures (LTBMC) and up-regulated IL-6 and IL-1α production by these cells in the infected mice, which was consistent with higher number of non-adherent cells. Additional studies to investigate the levels of interferon-gamma (INF-γ) in the supernatant of splenocyte cultures demonstrated a further increase in the level of this cytokine in infected-treated mice, compared to infected controls. In all cases, no differences were observed between the responses of the two optimal biologically effective doses. In contrast, no significant changes were produced by the treatment with the 50mg/kg dose. In addition, no changes were observed in normal mice treated with the three doses used. All together our results suggest that orally given Imunoglucan® indirectly modulates immune activity and probably disengages Listeria induced suppression of these responses by inducing a higher reserve of myeloid progenitors in the bone marrow in consequence of biologically active cytokine release (CSFs, IL-1α, IL-6, and INF-γ).

Bone marrow progenitor cells from chemically exposed workers display an intrinsic ability for autonomous proliferation.

In this study, the autonomous proliferation of bone marrow progenitor cells (CFU-C), a pathological phenomenon observed in many hematological abnormalities, was investigated in 31 individuals who had been diagnosed as having neutropenia. Of these subjects, 18 had been chronically exposed (range of exposure 5-30 years) to a variety of petroleum distillates. We observed that the group of exposed individuals presented higher numbers of autonomous CFU-C when compared with those unexposed subjects. In addition, follow-up data demonstrated that 20% of the exposed population (4 of the 18) developed malignant hematological diseases. The autonomous CFU-C obtained from all individuals studied was composed predominantly of macrophages. This suggests an involvement of these cells in the development of hematological abnormalities, probably as a result of increased production of chemical myelotoxic metabolites.

Contenção ativa para mordidas abertas esqueléticas tratadas ortodonticamente / Active retention for skeletal open bite treated orthodonticaly

A estabilidade nos tratamentos ortodônticos depende de uma série de fatores, tais como: alteração na forma dos arcos, tecidos gengivais e periodontais, dimensões dos incisivos inferiores, influência dos fatores ambientais e da neuromusculatura, crescimento pós-tratamento, os terceiros molares e a influência das caracteríticas da má oclusão original. Os autores pretendem abordar considerações sobre o crescimento dento-facial pós-tratamento e suas implicações na recidiva, assim como a proposição de uma contenção ativa para este tipo de maloclusão. Será apresentada uma contenção ativa na forma de uma placa de Hawley associada a um "bite block" a ser usada em pacientes com padrões esqueléticos de mordida aberta e crescimento remanescente